Dr. Michael Welner, a forensic psychiatrist who is chairman of The Forensic Panel, a practice in New York City, has worked on mass-shooting cases for many years and shared some general thoughts about these kinds of incidents:
“Mass shooting cases have the common motive of an attacker seeking immortality. Each of the attackers have different degrees of paranoia and resentment of the broader community. Some are so paranoid that they’re psychotic. Others are paranoid in a generally resentful way but have no significant psychiatric illness. But you have to hate everyone in order to kill anyone. The threshold that the mass shooter crosses is one in which he decides that his righteous indignation and entitlement to destroy is more important than the life of any random person that he might kill.”
“This is why mass shooting are invariably, invariably carried out by people who have had high self esteem. They are people who had high expectations of themselves. It’s not at all surprising to hear about these crimes in people who either valued their own intelligence or their own career prospects at one time.”
“They’re people who are unfailingly unable to form satisfying sexual attachments and their masculinity essentially gets replaced with their fascination for destruction.”
“The overwhelming majority of folks who do this are male because of how, in our culture, masculine identity is so closely tied to the capacity to destroy.”from Colorado theater shooting blog
"We are gazing here into deep secrets of human experience. If a man unfolds the element of antipathy in his life of feeling so strongly that it plays into his waking life, his whole being is permeated with antipathy which then lays hold of his astral body; his astral body is steeped in the element of antipathy; antipathy streams out from him like an abnormal aura. It may then happen that he begins to feel antipathy to people to whom his attitude was otherwise neutral, or indeed even to those he loved or knew intimately. These conditions can give rise to persecution mania in all its forms. WHEN FEELINGS OF ANTIPATHY NOT TO BE EXPLAINED BY OUTER CIRCUMSTANCES ARE EXPERIENCED, THIS IS DUE TO THE OVERFLOWING ANTIPATHIES IN THE SOUL, THAT IS TO SAY, TO AN ABNORMAL INTENSIFICATION OF THE ONE POLE IN THE LIFE OF SOUL WHICH FORCES ITS WAY UPWARDS OUT OF SLEEP. If this antipathy gets the upper hand in a human being, he becomes a world-hater, and such hatred can assume incredible proportions. The aim of all education and all social endeavor should be to prevent human beings from becoming world-haters.
"We [humans in general] have no knowledge at all of how this inner will permeates our limbs, our entire organism. The most that can be said is that now and then, through strange dreams, something comes up into the consciousness of what lies in the will that works in our organism during sleep. WHAT LIVES IN THIS WILL LIES AND RIGHTLY SO FOR THE ORDINARY CONSCIOUSNESS ON YONDER SIDE OF THE THRESHOLD. HE WHO COMES TO KNOW IT, LEARNS TO KNOW THE FORCE BY WHICH THE HUMAN BEING CAN BE LED TO THE UTTERMOST EVIL.
"Let it be remembered that nothing in the world is in itself evil or good. WHAT IS RADICALLY EVIL WHEN IT BREAKS INTO OUR CONSCIOUS LIFE, is the counterbalance for our spent life-forces [which is good] when it takes effect in its right place, namely as the regulator of organic activity during the sleeping state. [emphasis added]
"If you ask: What is the nature of the forces which make compensation for the spent life-forces? the answer is: They are the forces of evil. Evil has its mission and it is here."from The Sun-Mystery in the Course of Human History by Rudolf Steiner
Perhaps another way of putting it is that James Holmes became possessed by hatred. (I can understand how someone with such intelligence would become hostile as a result of being reduced to a job at McDonald's, thanks to the economic collapse.) I might be reading more into Steiner's description of a world-hater than I should. It just sounds a lot like Dr. Welner's description of the process that leads people into such horrendous, subhuman acts.
Other plausible factors are "antidepressants" and video games, or some combination.
But without guns, he's not a threat, so I suggest that we save the taxpayers some money by taking his guns and releasing him.